Semi-trailer dump body construction

ABSTRACT

A semi-trailer dump body construction affording improved lateral stability during dumping in which a hydraulic hoist is mounted below the dump body and support frame, positioned intermediate the fifth wheel connection and the tandem rear axle assembly of the frame so as to distribute the loading more uniformly over the tandem rear wheels and including alignment means mounted on either side of the hoist to minimize lateral movement of the hoist and dump body when the hoist is in the extended dump position.

United States Patent 1 Benninger et al.

[54] SEMI-TRAILER DUMP BODY CONSTRUCTION [7 51 Inventors: Arthur C.Benninger, Seneca; Meletus 1. Long, Brookville, both of [73] Assignee:Tri-Brook, lnc., Brookville, Pa. [22] Filed: Dec. 10, 1971 [21] Appl.No.: 206,832

[52] US. Cl. "298/22 R, 298/17 S [51] Int. Cl ..B60p l/04, 360p H28 [58]Field of Search ..298/22 R, 22 D, 22 B, 22 A,

298/22 P, l8, 17 S [56] v References Cited UNITED STATES PATENTS2,449,202 9/l948 Day ..298/22 P 2,999,721 9/1961 Wood ..298/22 P [451Jan. 23, 1973 FOREIGN PATENTS OR APPLICATlONS 567,690 12/1958 Canada298/22 P Primary ExaminerRichard J. Johnson Assistant Examiner-ReinhardEisenzopf Attorney-John M. Webb [57] ABSTRACT 3 Claims, 7 DrawingFigures SEMI-TRAILER DUMP BODY CONSTRUCTION This invention relatesgenerally to a semi-trailer dump body construction and more particularlyto a semi-trailer dump body construction which greatly increases thelateral stability of a semi-trailer during dumping operations.

Semi-trailers equipped with dump bodies are often used in connectionwith construction work. As such, it is frequently necessary that the payload be dumped while the semi-trailer is on unpaved and uneven terrain.Inherent with this working environment is the danger that thesemi-trailer may tip or laterally capsize as the dump body is raisedtoward the dump position. l-Ieretofore, the most common semi-trailerhoist construction becomes less stable as the dump body is raised.

Generally, in conventional semi-trailer dump body is mounted at thefront of the semi-trailer, above that portion of the frame whichconnects to the tractors fifth wheel. The stationary end of the hoist ispivotally connected to the semi-trailersupport frame above the tractorsrear wheels and the extensible end of the hoist is pivotally-connectedto the top portion of the dump body. The hoist of the conventionalsemi-trailer dump body is disposed in a chamber or closure known in theart as a dog box, in the front portion of the body, separated by a wallfrom that portion of the dump body into which the pay load is carried.

Due to the location of the hoist in the conventional semi-trailer,loading is concentrated at the ends of the support frame as the hoistraises the dump body. As the dump body inoves to the fully raisedposition, the center of gravity tends to shift toward the rear of thebody. This type of weight distribution tends to how the frame such-thatmost of the load is carried by the rearward wheels of the tandem rearaxle assembly. This leads to an unstable condition especially if therear wheels of the tandem axle are resting on a soft spot in the ground.With the extra load on the rearward wheels, there isa greater tendencyfor those wheels to sink in a soft spot than if the weight were moreevenly distributed overthe front and rear wheels of the tandem rear axleassembly.

If the semi-trailer is resting on uneven terrain won a soft spot duringdumping, the dump body will tend to lean or tilt laterally and become,as is referred to in the art, outof plumb. In the conventionalsemi-trailer dump body construction, this lateral leaning is accentuatedwhen the hoist is in its fully extended position due to the lateralmovement of the extended hoist and dump body. This additional body leanoften times exceeds the stable positionand is sufficient to allow thesemi-trailer to overturn.

The conventional semi-trailer dump body construction with the hoistmountedat the front of the dump body requires that the hoist be enclosedin a dog box. A portion of the pay load may stick in one of the cavitiesnext to this hoist enclosure. This is especially a problem when the payload is exposed to. freezing temperatures. Lateral stability isdecreased if the load on one side of the hoist enclosure sticks duringdumping. This unbalanced weight on one side of the raised dump body isoften times sufficient to cause the semi-trailer to'capsize, especiallyif the trailer is resting on'soft or uneven terrain during dumping.

Our invention eliminates many of the hazards inherent in the prior artby providing a laterally stabilized, semi-trailer dump body constructionwhich greatly reduces the risk of overturning during dumping operations.

Our invention increases the lateral stability of a semi- -trailer duringdumping operations by providing a hoist construction which minimizeslateral tilting of the hoist and dump body and also provides a moreuniform weight distribution on both the front and rear wheels of thetandem rear axle assembly. By providing a hoist construction whichminimizes lateral tilting of the hoist and dump body, our inventionmaintains lateral stability of a semi-trailer especially in thosesituations where the terrain is uneven; and by providing a hoistconstruction which causes a more uniform weight distribution on thefront and rear wheels of the tandem rear axle assembly, our inventionimproves lateral stability especially in those situations where theterrain is soft.

In accordance with our invention a semi-trailer is laterally stabilizedto reduce the hazard of capsizing during dumping operations by providinga hoist which is mounted beneath the dump body and support framerearward of the frames fifth wheel connection and forward of the tandemrear axle assembly of the semitrailer and including alignment meansmounted on either side of the cylinder portion of the hoist positionedadjacent the extensible portion to minimize lateral movement of thehoist and dump body during dumping.

The objects of our invention will become apparent by-referring to theaccompanying drawings, wherein:

FIG. 1 is a side view of a semi-trailer structure embodying theinvention, the semi-trailer being in the travel position;

FIG. 2 is a side view of a semi-trailer structure embodying theinvention with the dump body in the fully raised, dump position;

FIG. 3 is a side view of the hydraulic hoist construction showing oneembodiment of the hoist alignment means;

FIG. 4 is a rear view of the hoist construction and alignment means ofFIG. 3;

FIG. 5 is a sectional view taken along line VV'of FIG. 4;

FIG. 6 is a partial, front view of the hoist showing another embodimentof the hoist alignment means;

FIG. 7 is a partial, sectional view taken along line VII-VII of FIG. 6.t I

Referring now to thespecific details of the drawings, wherein like partsare designated by the same numeral throughout the various FIGS., FIGS. 1and 2 show the semi-trailer dump body construction of our invention. Thesemi-trailer designated generally 10 is transported by a tractor 15which attaches to the semi-trailers conventional fifth wheel whichgenerally is positioned above the tractors rear wheels 20. Thesemi-trailer 10 includes dump body 12 which has a forward-portion 24 anda discharge or rear portion 23.

The dump body 12 is positioned on the support frame designated generally11 and pivotally connected to the supportframe 11 by pivotal connection13 adjacent the rear portion 23 of the dump body 12. Included on therear portion of support frame 11 is the tandem rear axle assembly 33onto which are mounted the tandem rear wheels 25 (a) and 25 (b) whichsupport the rear of the semi-trailer. The front portion of support frame11 also includes fifth wheel connection means 22 positioned on the frame11 below the forward portion 24 of the dump body 12 for detachablysecuring the semi-trailer to the tractor 15.

A conventional hydraulic hoist generally designated 30 is employed totilt the dump body 12 about the pivotal connection 13. The hydraulichoist 30 includes a stationary cylinder portion 19 and a telescoping,extensible portion 21. The hoist 30 is positioned below the dump body 12and supported by hoist mounting means generally designated 14 which isattached to and depends below support frame 11.

Referring particularly to FIGS. 3 and 4, the hoist mounting means 14includes a first mounting member 34 and a second mounting member 35. Thehoist mounting members 34 and 35 are welded to the support frame 11 oneither side of its longitudinal center line. Hoist mounting members 34and 35 depend below the support frame 11 and are spaced laterallyopposite each other by an appropriate distance so as to permit themounting of the hoist 30 between them. The cylinder portion 19 of thehoist 30 is pivotally connected at one end to the hoist mounting means14 by pivotal connection 16 and the telescoping extensible portion 21 ofthe hoist 30 is pivotally connected to the underside of the dump body 12by pivotal connection 17. As can be seen in FIGS. 1, 2 and 3, thehydraulic hoist 30 is mounted at an angle such that the pivotalconnection 17 of the extensible portion is rearward that of pivotalconnection 16 of the cylinder portion. Such a mounting construction isdesirable since it provides a minimum of pivotal movement of the hoistduring the dumping operation and hence, closer lateral alignment can beachieved.

The hoist 30 is longitudinally positioned on the support frame 11rearward of the fifth wheel connection means 22 and forward of thetandem rear axle assembly 33 of the semi-trailer. By positioning thehoist 30 between the fifth wheel connection means 22 and the tandem rearaxle assembly 33, the lateral stability of the semi-trailer is increasedduring operations. As can be seen in FIG. 2, when the dump body 12 is inthe raised dump position, the loading is concentrated on the supportframe 11 at the rear pivotal connection 13 and at the hoist pivotalconnection 16. The load applied at the hoist pivotal connection 16 istransmitted by the hoist mounting means 14 to the support frame 11 whichforces that section of the frame intermediate the fifth wheel connectionmeans 22 and the tandem rear axle assembly 33 toward the ground. Whenthe frame 11 is loaded rearward the fifth wheel connection means 22, agreater portion of the load is transmitted to the forward wheels 25 (a)of the tandem rear axle assembly 33. At the same time during dumping,the rear wheels 25 (b) of the tandem rear axle assembly 33 are beingloaded by the weight concentrated at the rear pivotal connection 13.When weight is distributed more uniformly over the forward and rearwheels of the tandem rear axle assembly in this manner, the semi-trailerbecomes more stable especially on soft terrain.

The lateral stability of a semi-trailer is likewise improved whenlateral tilting of the extended hoist and dump body is minimized.Referring now to FIGS. 3-7,

the hoist alignment means 40 can best be seen. One embodiment of thehoist alignment means 40 is shown in FIGS. 3, 4, and 5. A pair ofreinforcing plates 28 with surfaces formed to match the curvature of thehoist 30 are attached to the cylinder portion 19 of the hoist 30 andpositioned on opposite sides of the cylinder portion 19 adjacent theextensible portion 21 of the hoist. A pair of wear plates 29 each havinga flat surface are attached to the reinforcing plates 28 on either sideof the cylinder portion 19 of the hoist 30. A pair of guide rails 27 areattached to mounting members 34 and 35 of the hoist mounting means 14 oneither side of the hoist 30 as best .seen in FIGS. 4 and 5. The guiderails 27 extend from hoist mounting members 34 and 35 and slidably abutthe wear plates 29. This alignment structure allows transverse movementof the hoist 30 about pivotal connection 16 of the cylinder portion 19but does not permit movement of the hoist 30 in the lateral direction.

Lateral movement of the hoist 30 and the dump body 12 is similarlyminimized by another embodiment of the hoist alignment means 40 shown inFIGS. 6 and 7. Guide channel 31 is attached to the cylinder portion 19of the hoist 30 adjacent the extensible portion 21. Guide channel 31extends outwardly on opposite sides of the hoist 30 and slidably abutsthe sides of the hoist mounting members 34 and 35. This alignmentstructure allows transverse movement of the hoist 30 about pivotalconnection 16 of cylinder portion 19 but does not permit movement ofhoist 30 in the lateral direction.

While the preferred embodiments of the present invention have been shownand described herein, it is obvious that many structural details may bechanged without departing from the spirit and scope of the appendedclaims.

What is claimed is:

1. A semi-trailer dump body construction affording improved lateralstability during dumping, which c'omprises:

a. a semi-trailer dump body having a front portion and a rear portion; asemi-trailer support frame having a front portion and a rear portion andincluding therewith fifth wheel connection means located adjacent thefront portion for attaching the semi-trailer to the fifth wheel of atractor and also including a rear axle assembly mounted adjacent therear portion of said support frame;

c. dump body mounting means for pivotally connecting said body to saidsupport frame positioned adjacent the rear portions of said body andsaid support frame;

d. hydraulic hoist means for tilting said body about said dump bodymounting means, said hoist means having a cylinder portion and anextensible portion;

. hoist mounting means for securing the hydraulic hoist below the dumpbody, said mounting means attached to and depending below the supportframe and longitudinally positioned between the fifth wheel connectionmeans and the rear axle assembly of the support frame;

f. means pivotally connecting the extensible portion of the hydraulichoist to the dump body;

g. means pivotally connecting the cylinder portion of the hydraulichoist to the hoist mounting means, below the support frame, said pivotalconnection means positioned forward of the pivotal connection means ofthe extensible portion so as to minimize pivotal movement of the hoistabout the pivotal connection means of the cylinder portion duringdumping operations;

h. hoist alignment means positioned at the cylinder portion of the hoistadjacent the extensible portion adjacent the extensible portion of thehoist;

. a pair of wear plates each having a flat surface attached to thereinforcing plates on opposite sides of the cylinder portion adjacentthe extensible portion of the hoist;

c. a pair of guide rails attached to the hoist mounting means on eitherside of the cylinder portion, said guide rails extending from the hoistmounting means and slidably abutting the wear plates on opposite sidesof the hoist so as to allow transverse movement of the hoist about thepivotal connection means of the cylinder portion and to prohibitmovement of the hoist in the lateral direction.

3. The semi-trailer dump body construction of claim 1, wherein the hoistalignment means includes a guide channel attached to the cylinderportion of the hoist adjacent the extensible portion, said channelextending outwardly on opposite sides from the cylinder portion andslidably abutting the sides of the hoist mounting means so as to allowtransverse movement of the hoist about the pivotal connection means ofthe cylinder po'r- 2. The semi-trailer dump body construction of claim1, wherein the hoist alignment includes:

a. a pair of reinforcing plates each having a curved tion and toprohibit movement of the hoist in the lateral direction.

1. A semi-trailer dump body construction affording improved lateralstability during dumping, which comprises: a. a semi-trailer dump bodyhaving a front portion and a rear portion; b. a semi-trailer supportframe having a front portion and a rear portion and including therewithfifth wheel connection means located adjacent the front portion forattaching the semi-trailer to the fifth wheel of a tractor and alsoincluding a rear axle assembly mounted adjacent the rear portion of saidsupport frame; c. dump body mounting means for pivotally connecting saidbody to said support frame positioned adjacent the rear portions of saidbody and said support frame; d. hydraulic hoist means for tilting saidbody about said dump body mounting means, said hoist means having acylinder portion and an extensible portion; e. hoist mounting means forsecuring the hydraulic hoist below the dump body, said mounting meansattached to and depending below the support frame and longitudinallypositioned between the fifth wheel connection means and the rear axleassembly of the support frame; f. means pivotally connecting theextensible portion of the hydraulic hoist to the dump body; g. meanspivotally connecting the cylinder portion of the hydraulic hoist to thehoist mounting means, below the support frame, said pivotal connectionmeans positioned forward of the pivotal connection means of theextensible portion so as to minimize pivotal movement of the hoist aboutthe pivotal connection means of the cylinder portion during dumpingoperations; h. hoist alignment means positioned at the cylinder portionof the hoist adjacent the extensible portion thereof, said alignmentmeans positioned on opposite sides of said hoist between the cylinderportion and the hoist mounting means to slidably align the cylinderportion so as to permit movement of the hoist about the pivotalconnection means of the cylinder portion and to prohibit movement of thehoist in the lateral direction during dumping operations.
 2. Thesemi-trailer dump body construction of claim 1, wherein the hoistalignment includes: a. a pair of reinforcing plates each having a curvedshape matching the curvature of the cylinder portion of the hoist, saidpair of reinforcing plates attached on opposite sides of the cylinderportion adjacent the extensible portion of the hoist; b. a pair of wearplates each having a flat surface attached to the reinforcing plates onopposite sides of the cylinder portion adjacent the extensible portionof the hoist; c. a pair of guide rails attached to the hoist mountingmeans on either side of the cylinder portion, said guide rails extendingfrom the hoist mounting means and slidably abutting the wear plates onopposite sides of the hoist so as to allow transverse movement of thehoist about the pivotal connection means of the cylinder portion and toprohibit movement of the hoist in the lateral direction.
 3. Thesemi-trailer dump body construction of claim 1, wherein the hoistalignment means includes a guide channel attached to the cylinderportion of the hoist adjacent the extensible portion, said channelextending outwardly on opposite sides from the cylinder portion andslidably abutting the sides of the hoist mounting means so as to allowtransverse movement of the hoist about the pivotal connection means ofthe cylinder portion and to prohibit movement of the hoist in thelateral direction.